(require 'org-eldoc)
(org-eldoc-hook-setup)
(add-hook 'emacs-lisp-mode-hook 'eldoc-mode)
(defun org-eldoc-documentation-function ()
  "Return breadcrumbs when on a headline, args for src block header-line,
  calls other documentation functions depending on lang when inside src body."
  (or
   (org-eldoc-get-breadcrumb)
   (org-eldoc-get-src-header)
   (let ((lang (org-eldoc-get-src-lang)))
     (cond ((or
             (string= lang "elisp")
             (string= lang "emacs-lisp"))
            (cond ((fboundp 'eldoc-documentation-function-default)
                   (eldoc-documentation-function-default))

                  ((locate-library "elisp-mode") ;; we're using development version of Emacs
                   (autoload 'elisp-eldoc-documentation-function "elisp-mode" nil t)
                   (elisp-eldoc-documentation-function))
                  (t                    ;24.3
                   (let (eldoc-documentation-function)
                     (eldoc-print-current-symbol-info)))))
           ((or
             (string= lang "c") ;; http://github.com/nflath/c-eldoc
             (string= lang "C")) (when (require 'c-eldoc nil t)
                                   (c-eldoc-print-current-symbol-info)))
           ;; https://github.com/zenozeng/css-eldoc
           ((string= lang "css") (when (require 'css-eldoc nil t)
                                   (css-eldoc-function)))
           ((string= lang "python") (when (require 'python nil t)
                                      (python-eldoc-function)))
           ;; https://github.com/zenozeng/php-eldoc
           ((string= lang "php") (when (require 'php-eldoc nil t)
                                   (php-eldoc-function)))
           ((or
             (string= lang "go")
             (string= lang "golang")) (when (require 'go-eldoc nil t)
                                        (go-eldoc--documentation-function)))))))